import java.util.Scanner;

public class Main1624 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double a = sc.nextDouble();
        double b = sc.nextDouble();
        double c = sc.nextDouble();
        double n=a+b+c;
        if (200<=n){
            System.out.println(String.format("%.1f",n*0.8));
        }else {
            System.out.println(String.format("%.1f",n*0.9));
        }

    }
}
